Hydraulic pump and motor



April 16, 1929. Y H s. HELESHAW ET`AL 1,709,194

HYDRAULIC PMP AND MOTOR Filed March 25, 19.27 2 shee'ssheef l Y i a Si 'A 1mm m. SQ o W 'prilvl6, 1929. H. s. HLE-SHAW ET AL ,709,l94

HYDRAULIC PUMP AND MOTOR Filed-March 25, 1927 2 sheets-sheer 2 Patented' Apr. 16, 1929.

' UNITED STATES PATENT OFFICE.

HENRY SELBY HELE-SHAW AND THOMAS EDWARD BEACHAM, or LONDON, ENGL'AND.

-` HYDRAULIC` PUMP .AND MOTOR.

Application led March 25, 1927, Serial 178,202, and in Great Britain April 26,1926.

The present invention consists of an improved method of varying the stroke of hydraulic pumps or motors of the type in which a number of -radial cylinders fitted with pistons and connecting rods working on a nonrotating crank cooperate with a cylindrical valve. In order to vary the stroke of such a machine it is necessary to provide a mechanism by means of which the crank can be moved relatively to the axis of rotation and it is necessary to ensure that at all times the axis of the crank shall be exactly parallel to the axis of rotation.

The present invention -conSists broadly of a hydraulic pump or motor of the kind having a rotary carrier provided with radial cylinders operating on a fixed crank carried by a sliding block movable radially to vary its throw, wherein the sliding block has laterally ,extending portions sliding between parallel plates arranged transversely to the axis of the pump or motor. The guide-way in which the crank pin carrying block slides may be formed in transversely arranged plate members secured at one side of the casing of the pump or motorand provided on its opposite side with a a bearing on which one end of the cylinder carrier rotates.

Accordingr to a further feature of the invention in a hydraulic pump or motor of the kind having fa rotary carrier provided with radial cylinders operating on a fixed crank of variable.thr0w,the valve ports ofthe passa ages leading to the rear ends of the cylinders in a cup-shaped carrier extend through the sides of the shaft of the carrier into a bearing so as to register during the rotation of the shaft with inlet and outlet ports provided in such bearing.

A manner of carrying out the inventionis illustrated by the accompan ing drawinvs in which` Figure 1 is a genera sectional e evation of a rotary pump or motor to which the invention is applied, Figure 2 is a sectional view on line B--B `Figure 1, the member carrying the guide-way in which the crank pin carryingblock slides being omitted from the lower half of the figure.

In these drawings 2 is the crank p in of a rotaryV pump of the kind having a series of radial cylinders 5a provided with truncated pistons 5? connected by rods 5 to the crank pin 2, the radial cylinders being carried by a cup-shaped carrier 5 vof which the end 5i is formed as a valve having ports 6 connected by a passage 7 to the ends of the closed ends of the cylinders 5a, the ports 6 registering during the rotation of the carrier 5 with ports 13c 1n a boss 13b formed on the fixed casing 13 of the pump or motor in the known manner, the valve 5i belng mounted on roller bearings 5e,

5f in the casing 13 and extended to form av driving or driven shaft 5d. On the inner end of the carrier 5 is fixed by screws 8*l a bearing or Jopurnal plate 8".

In the present invention an extension 2a of the crank pin 2 is fixed by a nut '2b in a cross or motor.

In the present example the lateral eXtenslons of the sliding block 10 are in the form of a disc 12 provided with bearing faces 12a and 12b which t accurately between the face 13e of the end plate 13 and the-face 11b of the guide-way plate 11.4

On the inner face of the guide-Way plate 11- is formed a boss 11c which carries the inner race 11d of a ball bearing 11e, the outer race 11f of the bearing being secured on the cylinder carrier 5.

The cross head or sliding block l() is fitted witha-rod 10a secured therein by a nut 10 and sliding in the direction of the slot of the guide-way ofthe plate ll in a bearing 13" in the casing 13, thebearing 13 being providedl l with a fluid gland 13g.

The cylinder carrier 5 may be made practically oil-tight by filling in the spaces between thecylinders and Securing over its open end an annular ring 16. This enables the'ou* casing 13 to be run emptyof oil as oil leaki lg past the pistons 5b will lill the carrier 5 and be held within the ring 16 by centrifugal force.

.In order to bore the cylinders 5 without making an opening through their closed ends an opening 5fg is provided in the diametrically opposite lside of the carrier 5 and tted with a screwed plug 8.

In the example shown the valve rotates in a the extension'12 of the slidingblock 10 of widely disposed bearing faces 12a and 12",

that is, constructing them in preferably oval form and with the length of the minor diam- CII -Way plate fixed nearthe end of the motor casing, said plate having a faced bearing surface on its outer side and a slotted radially arranged guide-Way for the sliding block, an outer plate forming the end of the pump cass ing and having-its inner surface faced to form a bearing, a sliding plate having continuous bearing surfaces on its opposite faces integral with said block but -disposed transversely to the axis of the pin, and slideable between the faced surfaces of the guidefway plate and the outer plate. A l

2. A hydraulic pump or motor comprising in combination, a fixed crank pin, a sliding block to which said pin is fastened, a guide- Way plate fixed near the vend of the motor casing, said plate having a faced bearing surface on its outer side and aslotted radially arranged guide-way for the sliding block, an outer plate forming the end of the pump casing and having its inner surface faced to form a bearing, va sliding disc having continuous bearing surfaces von its opposite faces integral With but disposed transversely7 to the axis on the pin, and slideable between the faced surfaces ofthe guide-Way plate and the outer plate. p

`3. A hydraulic pump ormotor comprising incombinatiom a fixed crank pin, a sliding block to Which said pin is fastened, a guide-` Way plate fixed near the end ofthe motor leasing, said plate having a faced bearing surface on its outer side and a slotted radially arranged guide-Way for the sliding block,

an outer plate forming theend of the pump casing and having its inner surface faced Vto form a bearing, an oval shdmg disc the minor axis of which is greater than the major circle ofthe crank pin and having continuous bearingl surfaces on its oppositefaces integral with but disposed transversely to the axis of the pin, and slideable between` the faced surfaces of the guide-Way plate and the outer plate.

4. A hydraulic pump or motor comprising in combination, a rotary cylinder carrier, a fixed crank pin, a sliding block to Which said pinis fastened, a guide-Way plate fixed near the end of the motor casing, said plate on its inner face having a bearing for said rotary carrier and on its outer surface being formed with a faced bearing surface and being provided with a slotted radially arranged guidei'vay for the sliding block, an outer plate forming the end of the pump casing and having its inner surface faced to form a. bearing ,a sliding plate having continuous bearing surfaces on its opposite faces, said sliding plate being integral with said block but disposed transversely to the axis of the crank pin, and slidel able between the faced surfaces ofthe guideway plate and the outer plate.

5. A hydraulic pump ormotor comprisinoq in combination an integral rotary Valve anc cylinder carrier, a fixed crank pin, a sliding block to Which said pin is fastened, a guide- Way plate fixed near the end of the motor casing, said plate having on its inner face a bearing for the rotary carrier and on its outer surfacehaving a faced bearing, said plate also being provided with a slotted radially arranged guide-Wayfor the sliding block, the rotary cylinder carrier being closed at one end by the guide-ivay plate, the opposite end of the carrier forming a rotary valve having passages leading from the cylinders in the carrier to ports in the cylindrical face of the valve adapted to register with corresponding ports formed in the bearing supporting the valve, an outer plate forming the end of the pump. casing andhaving. its inner surfacel faced to form a bearing, a sliding disc having vcontinuous bearing surfaces on its opposite faces integral with said sliding block but disposed transversely to the axis of the pin and slideable between the faced surfaces of the guide-Way plate and the outer plate.

In Witness whereof We affix our signatures.

HENRY SELBY HELE-SHAW. THOMAS EDVARD BEACHAM.. 

